U.S. patent number 6,587,688 [Application Number 09/561,623] was granted by the patent office on 2003-07-01 for providing telephone number data for international cellular roamer service.
This patent grant is currently assigned to Lucent Technologies Inc.. Invention is credited to Michael Dwayne Chambers, Chee Keong Lee, Tony Tuong Nguyen, Charles C. Teising.
United States Patent |
6,587,688 |
Chambers , et al. |
July 1, 2003 |
Providing telephone number data for international cellular roamer
service
Abstract
Apparatus and a method for providing international numbers in
order to implement international cellular roamer service. When a
roamer registers, the Visitor Location Register (VLR) serving the
roamer, queries the Home Location Register (HLR) record of the
roamer. The HLR tests whether the VLR is in a foreign country. If
so, the HLR provides numerical information, such as the roamer's
billing number, in international form, including the country code
of the HLR. Advantageously, the VLR is provided with international
numbers where appropriate, and the roamer can be accommodated
outside the roamer's home country.
Inventors: |
Chambers; Michael Dwayne
(Plainfield, IL), Lee; Chee Keong (Hilliard, OH), Nguyen;
Tony Tuong (Aurora, IL), Teising; Charles C.
(Naperville, IL) |
Assignee: |
Lucent Technologies Inc.
(Murray Hill, NJ)
|
Family
ID: |
26865371 |
Appl.
No.: |
09/561,623 |
Filed: |
May 2, 2000 |
Current U.S.
Class: |
455/433 |
Current CPC
Class: |
H04W
8/12 (20130101); H04W 4/00 (20130101) |
Current International
Class: |
H04Q
7/38 (20060101); H04Q 007/20 () |
Field of
Search: |
;455/403,410,414,422,432,433,445,455,461,552,560 ;370/401,466,467
;379/219,229,230 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
TIA, EIA 41D Internationalization: Submission to ANSI-41 (Standards
Body). C. Teising. Nov. 19, 1998. (See Especially 6.4.2.31, j &
k, p. 22)..
|
Primary Examiner: Le; Thanh Cong
Assistant Examiner: Ewart; James
Parent Case Text
RELATED APPLICATIONS
This Application claims the priority date of Provisional
Application Serial No. 60/169,785, filed on Dec. 9th, 1999, by the
inventors of this Application.
Claims
What is claimed is:
1. For an international roaming mobile call from a mobile station,
a method of providing to a serving mobile switching center (MSC),
an appropriate telephone number for processing said call,
comprising the steps of: a mobile station (MS) requesting
registration and providing its identification to said serving MSC;
said serving MSC requesting an associated Visitor Location Register
(VLR) to create a record for said MS; said VLR requesting data from
a Home Location Register (HLR) serving the identified MS; said HLR
determining that the request was generated by a VLR of another
country; said HLR converting telephone numbers of an HLR record for
said MS into a form acceptable to said VLR; said HLR transmitting
in a Mobile Application Part of a signaling message a record
comprising the converted telephone numbers to said VLR; and said
VLR requesting said serving MSC to serve said mobile; said mobile
station originating a call; and said MSC serving said mobile
station to control establishment of said call using information
stored in said VLR and said HLR.
2. The method of claim 1, wherein the step of converting comprises
the step of prefixing a country code of said HLR to telephone
numbers stored in nationally significant public telephone numbers
in said HLR record, to create a fully qualified international
public telephone number.
3. The method of claim 1, wherein the step of serving said mobile
station to control establishment of said call comprises the step of
converting one of the received converted fully qualified
international public telephone number from said VLR.
4. The method of claim 3, wherein said VLR converts one of said
received converted fully qualified international public numbers by
deleting a country code from a converted number whose country code
matches the country code of the VLR.
5. The method of claim 1, wherein the step of determining that the
request was generated by a VLR of another country, comprises the
steps of: extracting a wireless international number of said VLR
from the request message received from said VLR; identifying a
mobile country code of said wireless international number;
comparing said mobile country code with a list of mobile country
codes of said HLR; and if said mobile country code is not on said
list, determining that the request was generated by a VLR of
another country.
6. The method of claim 5, wherein said VLR converts received fully
qualified international public hot line numbers by deleting
prefixes when the prefixes to be deleted match the country code of
the VLR.
7. The method of claim 5, wherein said VLR converts received fully
qualified nationally significant public restricted dialing numbers
by deleting country code prefixes when the prefixes to be deleted
match the country code of the VLR.
8. The method of claim 1, wherein the step of controlling
establishment of said call comprises the step of using one of said
converted fully qualified international public telephone numbers
for a billing record for said call.
9. The method of claim 1, wherein said VLR converts received fully
qualified international public calling number display data by
deleting a calling number country code if that code matches a
country code of the VLR.
10. For an international roaming mobile call from a mobile station,
apparatus for providing to a serving mobile switching center (MSC),
an appropriate telephone number for processing said call,
comprising: means for receiving from a mobile station (MS) a
registration request providing its identification to said serving
MSC; said serving MSC comprising means for requesting an associated
Visitor Location Register (VLR) to create a record for said MS;
said VLR comprising means for requesting data from a Home Location
Register (HLR) serving the identified MS; said HLR comprising means
for determining that the request was generated by a VLR of another
country; said HLR comprising means for converting telephone numbers
of an HLR record for said MS into a form acceptable to said VLR;
said HLR comprising means for transmitting in a Mobile Application
Part of a signaling message a record comprising the converted
telephone numbers to said VLR; and said VLR comprising means for
requesting said MSC to serve said mobile; responsive to said mobile
station originating a call; said MSC serving said mobile station to
control establishment of said call using information stored in said
VLR and said HLR.
11. The apparatus of claim 10, wherein the means for converting
comprises means for prefixing a country code of said HLR to
telephone numbers stored in international public telephone numbers
in said HLR record, to create a fully qualified nationally
significant public telephone number.
12. The apparatus of claim 10, wherein the means serving said
mobile station to control establishment of said call comprises
means for converting one of the received converted fully qualified
international public telephone number from said VLR.
13. The apparatus of claim 12, wherein said VLR converts one of
said received converted fully qualified international public
numbers by deleting a country code from a converted number whose
country code matches the country code of the VLR.
14. The apparatus of claim 10, wherein the means for determining
that the request was generated by a VLR of another country,
comprises means for: extracting a wireless international number of
said VLR from the request message received from said VLR;
identifying a mobile country code of said wireless international
number; comparing said mobile country code with a list of mobile
country codes of said HLR; and if said mobile country code is not
on said list, determining that the request was generated by a VLR
of another country.
15. The apparatus of claim 14, wherein said VLR comprises means for
converting received fully qualified international public hot line
numbers by deleting country code prefixes when the prefixes to be
deleted match the country code of the VLR.
16. The apparatus of claim 14, wherein said VLR comprises means for
converting received fully qualified international public restricted
dialing numbers by deleting country code prefixes when the prefixes
to be deleted match the country code of the VLR.
17. The apparatus of claim 10, wherein the means for controlling
establishment of said call comprises means for using one of said
converted fully qualified international public telephone numbers
for a billing record for said call.
18. The apparatus of claim 10, wherein said VLR converts received
fully qualified international public calling number display data by
deleting a calling number country code if that code matches a
country code of the VLR.
Description
TECHNICAL FIELD
This invention relates to apparatus and a method for providing
roamer telephone numbers in an international setting.
BACKGROUND OF THE INVENTION
Roamer service is a cellular mobile wireless service that is
provided to customers who leave the area served by their home
mobile switching center (MSC), and the immediate geographic area
served by that MSC and associated MSCs for serving the geographic
area. When a mobile station (MS) registers outside its home area, a
remote MSC receives the registration request, and requests that a
Visitor Location Register (VLR) create a record for the roaming MS.
The VLR queries a Home Location Register (HLR) of the roaming MS in
order to notify the HLR of the present location of the MS, and to
obtain numerical data such as a call forwarding number and a
billing number for the roaming MS. Such data is required for
serving the roaming MS from the remote MSC, and is stored in the
VLR of the remote MSC.
A problem arises when the home MSC and the remote MSC are in
different countries. The telephone numbers that are stored in the
HLR and VLR are usually national telephone numbers which do not
include, for example, a country code. A problem of the prior art is
that the use of the normal telephone numbers stored in the HLR
would create ambiguities in the VLR, and make international roamer
service awkward or impossible.
SOLUTION
The above problem is solved and an advance is made over the
teachings of the prior art in accordance with this invention,
wherein an HLR in response to receipt of a request for VLR data,
tests whether the VLR is in the same country. If not, the HLR
prefixes its own country code for numbers stored in the HLR. For
call forwarding numbers, such numbers are stored in the HLR,
including a country code, if the call forwarding number is outside
the country of the HLR. The VLR then stores numbers pertaining to
countries outside the VLR's country to include a country code, but
continues to store numbers of the country in which the VLR resides
in the format of that country. Advantageously, such an arrangement
allows for the storage of international numbers where needed, and
national numbers where international numbers are not needed, and
facilitates the offering of international roamer service.
BRIEF DESCRIPTION OF THE DRAWING(S)
FIG. 1 is a block diagram, illustrating the operation of
Applicants' invention;
FIG. 2 is a flow diagram illustrating the operation of Applicants'
invention;
FIG. 3 is a flow diagram illustrating operations executed for calls
to the roamer; and
FIG. 4 illustrates operations performed when the roamer originates
a call.
DETAILED DESCRIPTION
FIG. 1 illustrates the operation of Applicants' invention. A mobile
station 1, having roamer capabilities, is in a foreign country and
turns on its power. This leads to a registration request 11, sent
by that mobile station to a remote mobile switching center (MSC) 2,
located in the foreign country. MSC 2 sends a registration request
12, to a Visitor Location Register (VLR) 3, serving that MSC. The
registration request asks the VLR to make a record of the presence
of MS 1, so that MS 1 can be served. VLR 3 communicates a
registration request 13, to a Home Location Register (HLR) 4,
serving MS 1. The HLR 4 tests the registration request 13 to
determine whether the registration request is from the same country
as the country of the HLR. If it is from the same country, the
methods of the prior art are used. If not, the HLR reports back to
the VLR, an international version of the subscriber data in a
response message 14. The international version includes an
international version of any call forwarding number stored in the
HLR. VLR 3 records all necessary data from the HLR in the
appropriate national or international format, and reports back to
MSC 2 in a message 15, that MS 1 is now registered and may be
served.
Several ANSI 41 messages includes parameters that contain digits
that are used during the processing of calls for roaming mobiles.
When a mobile is roaming inter-nationally, these digit parameters
must have international significance, (i.e., must contain E.164
country codes), so that they will give the desired result when they
are processed by the visited system.
Examples of the ANSI 41 messages and the associated digits
parameters that require internationalization include:
CHAPTER 5. SEC. MESSAGE DIGITS PARAMETER 6.4.2.13 Feature Request
Return Result Digits (Dialed) 6.4.2.30 Origination Request Return
Digits (Dialed) Result 6.4.2.31 Qualification Directive Invoke
Digits(Destination) DMH_Billing Digits Mobile Directory Number
Restriction Digits 6.4.2.37 Registration Notification Digits
(Destination) DMH_Billing Digits Mobile Directory Number
Restriction Digits 6.4.2.46 Transfer to Number Request Digits
(Destination) Return Result
Digit parameter internationalization can be accomplished as
follows: 1. When the mobile's home system recognizes that the
mobile is roaming internationally, then, as necessary, it
internationalizes the digits by prefixing its home country code to
the digits before sending the message. (The home country code is
the E.164 country code for the country where the system is
located.) For example, if the Digits (Destination) parameter
contains a forward-to number, then the home system analyzes the
number to determine whether it was entered into its database as a
national, or international number. If it was entered as a national
number, (which means that calls are to be forwarded within the
country where the home system is located), then the home system
prefixes its home country code to the forward-to number contained
in the Digits (Destination) parameter. If the forward-to number was
entered as an international number (i.e., with a country code),
then the home system does not modify the number before populating
it into the Digits (Destination) parameter. Similar processing is
done to internationalize other digits parameters that contain
numbers that are used to route calls, and to restrict calls from
being placed to certain numbers, and for other digits parameters
that contain a billing number of the mobile's directory number. If
the digits were previously entered into the home system's database
as an international number, then the home system does not modify
the number before populating it into the digits parameter. 2. When
the mobile's serving system receives from the home system, one of
these messages containing an internationalized digits parameter,
then, it compares its home country code with that contained in the
received parameter. If they differ, then the serving system
processes and uses the number in an international context. For
example, if the country code of the forward-to number contained in
the Digits (Destination) parameter differs from that of the serving
system, then the call is forwarded to that international
destination. If the home country code of the serving system is the
same as the country code of the forward-to number received in the
Digits (Destination) parameter, then, the serving system deletes
the country code from the parameter and processes and uses the
number in a national context. For example, if the country code of
the forward-to number is the same as that of the serving system,
then the call is forwarded within the country where the serving
system is located.
Completion of terminating calls to a roamer who has registered in a
foreign country is carried out in the following way. When a call
for an international roamer comes into the home system, the HLR
sends a route request to the visited system. The visited MSC, (such
as MSC 2, in which the roamer has registered), assigns a temporary
local directory number (TLDN), to the roamer. This TLDN is
forwarded to the VLR. The VLR recognizes that the HLR is in a
foreign country and adds the country code for that country to the
TLDN. The VLR then forwards the international TLDN to the HLR and
thence to the home MSC. The call is then routed, using the
international TLDN, to the roamer. The visited system prepares
billing records for any roamer calls.
The HLR determines that the VLR is located in a different country
by comparing the Mobile Country Code (MCC) of the VLR with the
HLR's list of home country MCCs. An internationalized
identification number, called an E.212 number, consists of a three
digit MCC and a National Mobile Station Identity (NMSI). Each MCC
code is uniquely assigned to one country. The E.212 is a
non-dialable number used to identify units of the mobile network,
such as VLRs, HLRs, switches, cell sites, etc.; or used to identify
mobile stations (in which role, it is also called an IMSI
(International Mobile Station Identity)). The number that is dialed
to place a call to a mobile station is a conventional E.164 number
consisting of a country code and a nation specific number.
FIG. 2 is a flow diagram illustrating the operation of Applicants'
invention. A mobile station requests registration, and in doing so,
provides its international mobile station identifier (IMSI), or
some other mobile station identity, (Action Block 201). The serving
mobile switching center (MSC), (i.e., the MSC serving the mobile
station at the time of the request for registration), requests its
associated VLR to create a record for that mobile station, (Action
Block 203). The VLR requests data from the HLR of that mobile
station, (Action Block 205). Next, it is determined whether the
request was from a foreign VLR, (Test 207). If not, then the
registration is processed as in the prior art, (Action Block 209).
If the request was from a foreign VLR, the national telephone
numbers stored in the HLR are converted to an international format
by prefixing the country code of that HLR, (Action Block 211). The
converted numbers are then transmitted to the VLR, (Action Block
213). The VLR requests the serving MSC to serve said mobile,
(Action Block 215), by placing that mobile's identification in its
list of served mobiles.
FIG. 3 illustrates operations for serving a call terminating to the
roamer. When a call is received for the roamer, the call is
originally routed to the home MSC, (Action Block 301, FIG. 3). The
home MSC sends a location request to the HLR, (Action block 303).
The HLR sends a route request to the VLR, (Action Block 305). The
VLR sends a route request to the serving (visited) MSC, (Action
Block 307). The MSC assigns a TLDN for the call, and informs the
VLR, (Action Block 309). The VLR tests if the HLR is located in a
different country, and if so, adds the country code to the TLDN,
(Action Block 311). The VLR then forwards the international TLDN to
the HLR, (Action Block 313). The HLR forwards the international
TLDN to the home MSC, (Action Block 315). The home MSC then routes
the call to the destination specified by the international TLDN,
(Action Block 317).
FIG. 4 illustrates operations for serving a call originated by the
roamer. At some time after registration, the mobile station may
originate a call, (Action Block 401). The serving MSC controls
establishment of calls from that mobile using the records stored in
the VLR, (Action Block 403).
Among the services provided for some mobile users, is restricted
dialing privileges. For example, the user may not be allowed to
dial certain office codes, (usually within his country), or certain
country codes. These restrictions move with a roaming mobile user.
For this case, the HLR prefixes its country code to the restricted
in-country office codes and sends this information to the VLR. A
foreign VLR inspects the internationalized restriction data and
deletes the country code if it is the same as that of the VLR.
Another service provided from some mobile users is "hot line"
service. The user presses one or two buttons, and this is
interpreted as a request to be connected to a specific destination
number. Hot-line numbers stored in the VLR are edited to delete
country codes from those numbers whose country code matches that of
the VLR.
For calling number display, when the HLR requests a TLDN from the
serving MSC, the HLR forwards the calling party's number in an
internationalized form if the VLR is in a different country. The
VLR deletes the country code if the calling party's country code is
the same as that of the VLR. This is useful if someone in the VLR's
country is calling the roamer. Advantageously, this allows the
roamer to dial the displayed number to reach the caller.
The above is a description of one preferred embodiment of
Applicants' invention. Other embodiments will be apparent to those
of ordinary skill in the art, without departing from the scope of
the invention. The invention is only limited by the attached
Claims.
* * * * *